Dhindsa R S
Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada.
Plant Physiol. 1991 Feb;95(2):648-51. doi: 10.1104/pp.95.2.648.
The activities of glutathione reductase (EC 1.6.4.2), glutathione peroxidase (EC 1.11.1.9), and glutathione S-transferase (EC 2.5.1.18) were found to increase during slow drying or during rehydration following rapid drying of the drought-tolerant moss Tortula ruralis. Little change was observed in the activity of malate deydrogenase (NAD(+) oxidoreductase, EC 1.1.1.37) during dehydration or subsequent rehydration. When the tissue was treated with cycloheximide, actinomycin D, or cordycepin, the increase in the activities of glutathione reductase and glutathione S-transferase was largely prevented while effect on glutathione peroxidase was much smaller. Concomitantly, oxidized glutathione (GSSG) as percentage of total glutathione increased. GSSG level was correlated positively with the levels of lipid peroxidation and solute leakage and negatively with the rate of protein synthesis. The results show that GSSG level is a good indicator of oxidation stress and provide support to the suggestion that GSSG mediates, at least in part, the drought stress-induced inhibition of protein synthesis.
研究发现,耐旱苔藓小墙藓在缓慢干燥过程中或快速干燥后的复水过程中,谷胱甘肽还原酶(EC 1.6.4.2)、谷胱甘肽过氧化物酶(EC 1.11.1.9)和谷胱甘肽S-转移酶(EC 2.5.1.18)的活性会增加。在脱水或随后的复水过程中,苹果酸脱氢酶(NAD(+)氧化还原酶,EC 1.1.1.37)的活性变化不大。当用放线菌酮、放线菌素D或虫草素处理组织时,谷胱甘肽还原酶和谷胱甘肽S-转移酶活性的增加在很大程度上受到抑制,而对谷胱甘肽过氧化物酶的影响要小得多。与此同时,氧化型谷胱甘肽(GSSG)占总谷胱甘肽的百分比增加。GSSG水平与脂质过氧化水平和溶质渗漏呈正相关,与蛋白质合成速率呈负相关。结果表明,GSSG水平是氧化应激的良好指标,并支持了GSSG至少部分介导干旱胁迫诱导的蛋白质合成抑制这一观点。